This invention relates generally to processing of vibration data obtained from epicyclic gear trains, and more particularly to a method of performing selection time filtered signal averaging on vibration data from such gear trains.
The multiplicity of identical planet gears in an epicyclic gearbox, combined with the fact that the planet gear axes move in relation to the gearbox casing, make traditional vibration analysis techniques ineffective in the diagnosis of planet gear faults. The inability to effectively diagnose faults in epicyclic gearboxes is of particular concern in helicopters, most of which use epicyclic reduction gears as the final drive to the main rotor. Accordingly, there is need for more effective fault diagnosis techniques, and particularly as respects helicopter epicyclic gear trains, for reasons that include enhancement of safety.